Efficacy and safety of meropenem (3 g daily) in Japanese patients with refractory respiratory infections.

INTRODUCTION: Pneumonia is the third leading cause of mortality in Japan. In 2011, the use of meropenem (MEPM) at 3 g daily was approved to treat refractory infections in Japan. However, little has been reported on the clinical efficacy and safety of this regimen in Japanese patients with refractory infections.

OBJECTIVES: This study prospectively assessed the clinical efficacy and safety of MEPM (3 g daily) in Japanese patients with refractory pneumonia and/or intrapleural infections.

METHODS: This study was performed at our university hospital and affiliated hospitals. The plasma concentrations of MEPM before and one and four hours after MEPM administration were also evaluated.

RESULTS: A total of 48 patients were enrolled for the efficacy and safety evaluations. The response rate to MEPM (3 g daily) treatment was 90.9% (40/44). Adverse drug reactions were observed in 17 of the 48 patients (20.8%), and all improved after the cessation of MEPM. The plasma MEPM concentration one hour after administering 1 g of MEPM was 44.9 ± 12.0 μg/ml. A pharmacokinetic analysis revealed that the percentage of time above the MIC/24 h for an MIC of 4 μg/ml or 8 μg/ml was more than 50% in 12 of 13 (92%) and in nine of the 13 patients (69%), respectively, indicating sufficient efficacy of 3 g daily of MEPM.

CONCLUSION: Treatment with MEPM (3 g daily) in Japanese patients with refractory pneumonia and/or intrapleural infections is effective, with sufficient plasma concentrations of MEPM, and the treatment has a relatively good safety profile.